The objectives of this study were to set up a new genetic evaluation procedure to predict the breeding values of Holstein herds in Heilongjiang Province of China for milk and fat production by utilizing Canadian pedig...The objectives of this study were to set up a new genetic evaluation procedure to predict the breeding values of Holstein herds in Heilongjiang Province of China for milk and fat production by utilizing Canadian pedigree and genetic evaluation information and to compare the breeding values of the sires from different countries. The data used for evaluating young sires for the Chinese Holstein population consisted of records selected from 21 herds in Heilongjiang Province. The first lactation records of 2 496 daughters collected in 1989 and 2000 were analyzed. A single-trait animal model including a fixed herd-year effect, random animal and residual effects was used by utilizing Canadian pedigree and genetic evaluation information of 5 126 sires released from the Canadian Dairy Network in August 2000. The BLUP procedure was used to evaluate all cattle in this study and the Estimated Breeding Values (EBV)for milk and fat production of 6 697 cattle (including 673 sires and 6 024 cows) were predicted. The genetic levels of the top 100 sires originated from different countries were compared. Unlike the BLUP procedure that is being used in conjunction with the single-trait sire model in Heilongjiang Province of China now, the genetic evaluation procedure used in this study not only can be used simultaneously to evaluate sires and cows but also increase the accuracy of evaluation due to using the relationships and genetic values of the Canadian evaluated sires with more daughters. The results showed that the new procedure was useful for genetic evaluation of dairy herds and the comparison of the breeding values of these sires imported from different countries showed that a significant genetic improvement has been achieved for milk production of the Heilongjiang Holstein dairy population by importing sires from foreign countries, especially from the United States due to the higher breeding values.展开更多
Ovarian activitly in 10 postpartum Chinese-Holstein cows was monitored by ultrasonography every other day, stared from day 3 postpartum and finished by the end of a normal ovarian cycle. Meanwhile, the concentrations ...Ovarian activitly in 10 postpartum Chinese-Holstein cows was monitored by ultrasonography every other day, stared from day 3 postpartum and finished by the end of a normal ovarian cycle. Meanwhile, the concentrations of progesterone and 17β-oestradiol in peripheral plasma of the cows were measured by radioimmunoassay (RIA). The resutis showed that the first postpartum ovulation was found in 67% of the cows on the ovary opposed to the gravid horn. The first dominant foillicles ovulated for the six of ten cows. The time intervals from calving to the first ovulation were significantly associated with the number of follicular waves (r=0.83, P<0.01). No difference between the diameters of the first and the second ovulated follicles was found in the study, however, the growth rates of the first and the second ovulated follicles were significantly different (P<0.05), and the concentrations of 17β-oestradiol prior to the first ovulation were significantly lower than that before the second ovulation.展开更多
【目的】奶牛体外胚胎生产-移植(in vitro embryo production and embryo transfer,IVP-ET)是现代奶牛养殖的重要繁殖手段之一。为解析奶牛体外胚胎移植受胎率的影响因素,本研究利用大规模数据分析了荷斯坦牛体外胚胎移植受胎率的表型特...【目的】奶牛体外胚胎生产-移植(in vitro embryo production and embryo transfer,IVP-ET)是现代奶牛养殖的重要繁殖手段之一。为解析奶牛体外胚胎移植受胎率的影响因素,本研究利用大规模数据分析了荷斯坦牛体外胚胎移植受胎率的表型特征,为优化体外胚胎生产移植技术体系提供可用信息。【方法】本研究收集了11个规模化奶牛场4534头荷斯坦牛的5155条体外胚胎移植记录及其对应的孕检记录,采用Logistic回归模型分析各非遗传因素(如胚胎因素等)对奶牛体外胚胎移植受胎率的影响。【结果】荷斯坦青年牛体外胚胎移植总体受胎率为51.29%。胚胎因素(保存状态、发育阶段、体外培养天数)及受体牛移植次数对移植受胎率有极显著影响,其中,移植新鲜胚胎的受胎率极显著高于冷冻胚胎(P<0.01);不同发育阶段的胚胎中,发育至扩张囊胚的受胎率极显著高于囊胚(P<0.01);体外培养天数不同的胚胎中,培养至第6天下午、第7天上午及下午的胚胎的移植受胎率均极显著高于培养至第8天下午的胚胎(P<0.01);首次移植的受胎率极显著高于非首次移植(P<0.01)。受体牛月龄和胚胎父本对移植受胎率有显著影响,其中>14.5且≤15月龄受体牛的受胎率最高(52.59%),且极显著高于<14月龄的受体牛(P<0.01);胚胎父本显著影响移植受胎率(P<0.05),表明由父本决定的胚胎内在质量是影响移植成功与否的关键生产端因素,进一步提示胚胎生产与胚胎移植息息相关。【结论】基于大规模胚胎移植记录,本研究发现胚胎保存状态、发育阶段、体外培养天数及受体牛移植次数对移植受胎率有显著影响,优化胚胎质量与选择适宜受体是提高荷斯坦牛体外胚胎移植受胎率的关键。展开更多
旨在研究荷斯坦牛和湘西黄牛瘤胃发酵参数及微生物区系的差异,为探索不同遗传背景的动物瘤胃微生物生态系统的组成和和功能特征提供参考,同时也为品种特异性饲养策略的制定提供科学依据。选择状态良好的成年荷斯坦牛(241.3±9.1 kg...旨在研究荷斯坦牛和湘西黄牛瘤胃发酵参数及微生物区系的差异,为探索不同遗传背景的动物瘤胃微生物生态系统的组成和和功能特征提供参考,同时也为品种特异性饲养策略的制定提供科学依据。选择状态良好的成年荷斯坦牛(241.3±9.1 kg)和湘西黄牛(206.0±8.4 kg)各12头作为试验对象,所有试验动物均饲喂其常规饲粮。试验采集瘤胃液进行瘤胃发酵参数测定,同时应用16S rRNA测序分析瘤胃微生物群落结构和功能。结果表明:1)湘西黄牛的干物质消化率(DMD)、有机物消化率(OMD)、中性洗涤纤维消化率(NDFD)和酸性洗涤纤维消化率(ADFD)均显著高于荷斯坦牛(P<0.001)。2)湘西黄牛的瘤胃pH显著高于荷斯坦牛(P<0.001);湘西黄牛的瘤胃溶解氢(dH2)、溶解甲烷(dCH4)和氨态氮(NH3-N)浓度显著低于荷斯坦牛(P<0.001),而溶解氢与溶解甲烷比值(dH2/dCH4)显著高于荷斯坦牛(P<0.001);瘤胃发酵产物中,荷斯坦牛的总挥发性脂肪酸(TVFA)浓度及丙酸、丁酸、异丁酸、戊酸和异戊酸摩尔比例更高,而湘西黄牛的乙酸摩尔比例和乙丙比更高(P<0.001)。3)α多样性结果显示,湘西黄牛拥有更丰富和多样性的瘤胃微生物群落;荷斯坦牛瘤胃中主要差异富集了有益杆状菌属(Agathobacter)、丁酸弧菌属(Butyrivibrio)和毛螺菌属(Lachnospira)等功能菌(P<0.05),而湘西黄牛瘤胃微生物中主要差异富集了纤维杆菌门(Fibrobacteres)、糖发酵菌属(Saccharofermentans)、慢生微菌属(Lentimicrobium)、解琥珀酸菌属(Succiniclasticum)和醋杆菌属(Acetatifactor)等功能菌(P<0.05)。4)碳水化合物代谢通路(Carbohydrate metabolism)和其他氨基酸的代谢通路(Metabolism of other amino acids)在荷斯坦牛中显著富集(P<0.05),核苷酸代谢通路(Nucleotide metabolism)和其他次级代谢的生物合成通路(Biosynthesis of other secondary metabolites)在湘西黄牛中显著富集(P<0.05)。上述结果表明,荷斯坦牛和湘西黄牛营养物质消化率、瘤胃发酵参数及瘤胃微生物区系存现明显差异;荷斯坦牛瘤胃偏向丙酸型发酵模式,对非纤维植物多糖和蛋白质的消化能力更强;湘西黄牛瘤胃偏向乙酸型发酵模式,对纤维类物质的消化能力更强。展开更多
旨在系统鉴定奶牛中与基因表达显著相关的短串联重复序列(expression short tandem repeats,eSTRs),解析其在调控基因表达及复杂经济性状中的作用,为奶牛分子育种提供功能变异资源。本研究选用108头中国荷斯坦牛进行尾静脉血样采集,提...旨在系统鉴定奶牛中与基因表达显著相关的短串联重复序列(expression short tandem repeats,eSTRs),解析其在调控基因表达及复杂经济性状中的作用,为奶牛分子育种提供功能变异资源。本研究选用108头中国荷斯坦牛进行尾静脉血样采集,提取基因组DNA和总RNA,分别进行30×深度全基因组重测序和转录组测序。因部分样本质量较差,最终保留105头样本用于分析。对于遗传变异,利用TRF和HipSTR完成STR群体规模的注释和定量。对于基因表达,以Trimmomatic进行质量控制,STAR比对到参考基因组以及edegR定量。接着,以基因转录起始位点±1 Mb范围为窗口,采用线性模型将基因表达与STR进行关联分析,鉴定得到cis-eSTR。之后结合加权共表达网络分析(weighted correlation network analysis,WGCNA)及Gene Ontology(GO)富集分析,探索其在复杂性状中的潜在功能。共鉴定出25154对显著的cis-eSTR-基因表达关联,cis-eSTR主要分布于内含子区及转录起始位点附近。加权基因共表达网络分析显示,受cis-eSTR调控的基因被划分为多个功能模块,部分模块与奶牛的产奶及免疫相关性状显著相关。GO富集分析显示,这些模块广泛参与免疫应答、脂质代谢、细胞周期、DNA复制与稳定性等生物过程。多个关键基因(如IRF7、BoLA-DRB、CCT2等)在免疫调控与乳腺功能中具有潜在功能意义。cis-eSTR在调控奶牛基因表达和复杂性状方面具有重要作用。本研究所构建的cis-eSTR资源为奶牛健康等复杂性状的遗传机制研究和分子育种实践提供了功能注释信息标记。展开更多
文摘The objectives of this study were to set up a new genetic evaluation procedure to predict the breeding values of Holstein herds in Heilongjiang Province of China for milk and fat production by utilizing Canadian pedigree and genetic evaluation information and to compare the breeding values of the sires from different countries. The data used for evaluating young sires for the Chinese Holstein population consisted of records selected from 21 herds in Heilongjiang Province. The first lactation records of 2 496 daughters collected in 1989 and 2000 were analyzed. A single-trait animal model including a fixed herd-year effect, random animal and residual effects was used by utilizing Canadian pedigree and genetic evaluation information of 5 126 sires released from the Canadian Dairy Network in August 2000. The BLUP procedure was used to evaluate all cattle in this study and the Estimated Breeding Values (EBV)for milk and fat production of 6 697 cattle (including 673 sires and 6 024 cows) were predicted. The genetic levels of the top 100 sires originated from different countries were compared. Unlike the BLUP procedure that is being used in conjunction with the single-trait sire model in Heilongjiang Province of China now, the genetic evaluation procedure used in this study not only can be used simultaneously to evaluate sires and cows but also increase the accuracy of evaluation due to using the relationships and genetic values of the Canadian evaluated sires with more daughters. The results showed that the new procedure was useful for genetic evaluation of dairy herds and the comparison of the breeding values of these sires imported from different countries showed that a significant genetic improvement has been achieved for milk production of the Heilongjiang Holstein dairy population by importing sires from foreign countries, especially from the United States due to the higher breeding values.
文摘Ovarian activitly in 10 postpartum Chinese-Holstein cows was monitored by ultrasonography every other day, stared from day 3 postpartum and finished by the end of a normal ovarian cycle. Meanwhile, the concentrations of progesterone and 17β-oestradiol in peripheral plasma of the cows were measured by radioimmunoassay (RIA). The resutis showed that the first postpartum ovulation was found in 67% of the cows on the ovary opposed to the gravid horn. The first dominant foillicles ovulated for the six of ten cows. The time intervals from calving to the first ovulation were significantly associated with the number of follicular waves (r=0.83, P<0.01). No difference between the diameters of the first and the second ovulated follicles was found in the study, however, the growth rates of the first and the second ovulated follicles were significantly different (P<0.05), and the concentrations of 17β-oestradiol prior to the first ovulation were significantly lower than that before the second ovulation.
文摘【目的】奶牛体外胚胎生产-移植(in vitro embryo production and embryo transfer,IVP-ET)是现代奶牛养殖的重要繁殖手段之一。为解析奶牛体外胚胎移植受胎率的影响因素,本研究利用大规模数据分析了荷斯坦牛体外胚胎移植受胎率的表型特征,为优化体外胚胎生产移植技术体系提供可用信息。【方法】本研究收集了11个规模化奶牛场4534头荷斯坦牛的5155条体外胚胎移植记录及其对应的孕检记录,采用Logistic回归模型分析各非遗传因素(如胚胎因素等)对奶牛体外胚胎移植受胎率的影响。【结果】荷斯坦青年牛体外胚胎移植总体受胎率为51.29%。胚胎因素(保存状态、发育阶段、体外培养天数)及受体牛移植次数对移植受胎率有极显著影响,其中,移植新鲜胚胎的受胎率极显著高于冷冻胚胎(P<0.01);不同发育阶段的胚胎中,发育至扩张囊胚的受胎率极显著高于囊胚(P<0.01);体外培养天数不同的胚胎中,培养至第6天下午、第7天上午及下午的胚胎的移植受胎率均极显著高于培养至第8天下午的胚胎(P<0.01);首次移植的受胎率极显著高于非首次移植(P<0.01)。受体牛月龄和胚胎父本对移植受胎率有显著影响,其中>14.5且≤15月龄受体牛的受胎率最高(52.59%),且极显著高于<14月龄的受体牛(P<0.01);胚胎父本显著影响移植受胎率(P<0.05),表明由父本决定的胚胎内在质量是影响移植成功与否的关键生产端因素,进一步提示胚胎生产与胚胎移植息息相关。【结论】基于大规模胚胎移植记录,本研究发现胚胎保存状态、发育阶段、体外培养天数及受体牛移植次数对移植受胎率有显著影响,优化胚胎质量与选择适宜受体是提高荷斯坦牛体外胚胎移植受胎率的关键。
文摘旨在研究荷斯坦牛和湘西黄牛瘤胃发酵参数及微生物区系的差异,为探索不同遗传背景的动物瘤胃微生物生态系统的组成和和功能特征提供参考,同时也为品种特异性饲养策略的制定提供科学依据。选择状态良好的成年荷斯坦牛(241.3±9.1 kg)和湘西黄牛(206.0±8.4 kg)各12头作为试验对象,所有试验动物均饲喂其常规饲粮。试验采集瘤胃液进行瘤胃发酵参数测定,同时应用16S rRNA测序分析瘤胃微生物群落结构和功能。结果表明:1)湘西黄牛的干物质消化率(DMD)、有机物消化率(OMD)、中性洗涤纤维消化率(NDFD)和酸性洗涤纤维消化率(ADFD)均显著高于荷斯坦牛(P<0.001)。2)湘西黄牛的瘤胃pH显著高于荷斯坦牛(P<0.001);湘西黄牛的瘤胃溶解氢(dH2)、溶解甲烷(dCH4)和氨态氮(NH3-N)浓度显著低于荷斯坦牛(P<0.001),而溶解氢与溶解甲烷比值(dH2/dCH4)显著高于荷斯坦牛(P<0.001);瘤胃发酵产物中,荷斯坦牛的总挥发性脂肪酸(TVFA)浓度及丙酸、丁酸、异丁酸、戊酸和异戊酸摩尔比例更高,而湘西黄牛的乙酸摩尔比例和乙丙比更高(P<0.001)。3)α多样性结果显示,湘西黄牛拥有更丰富和多样性的瘤胃微生物群落;荷斯坦牛瘤胃中主要差异富集了有益杆状菌属(Agathobacter)、丁酸弧菌属(Butyrivibrio)和毛螺菌属(Lachnospira)等功能菌(P<0.05),而湘西黄牛瘤胃微生物中主要差异富集了纤维杆菌门(Fibrobacteres)、糖发酵菌属(Saccharofermentans)、慢生微菌属(Lentimicrobium)、解琥珀酸菌属(Succiniclasticum)和醋杆菌属(Acetatifactor)等功能菌(P<0.05)。4)碳水化合物代谢通路(Carbohydrate metabolism)和其他氨基酸的代谢通路(Metabolism of other amino acids)在荷斯坦牛中显著富集(P<0.05),核苷酸代谢通路(Nucleotide metabolism)和其他次级代谢的生物合成通路(Biosynthesis of other secondary metabolites)在湘西黄牛中显著富集(P<0.05)。上述结果表明,荷斯坦牛和湘西黄牛营养物质消化率、瘤胃发酵参数及瘤胃微生物区系存现明显差异;荷斯坦牛瘤胃偏向丙酸型发酵模式,对非纤维植物多糖和蛋白质的消化能力更强;湘西黄牛瘤胃偏向乙酸型发酵模式,对纤维类物质的消化能力更强。
文摘旨在系统鉴定奶牛中与基因表达显著相关的短串联重复序列(expression short tandem repeats,eSTRs),解析其在调控基因表达及复杂经济性状中的作用,为奶牛分子育种提供功能变异资源。本研究选用108头中国荷斯坦牛进行尾静脉血样采集,提取基因组DNA和总RNA,分别进行30×深度全基因组重测序和转录组测序。因部分样本质量较差,最终保留105头样本用于分析。对于遗传变异,利用TRF和HipSTR完成STR群体规模的注释和定量。对于基因表达,以Trimmomatic进行质量控制,STAR比对到参考基因组以及edegR定量。接着,以基因转录起始位点±1 Mb范围为窗口,采用线性模型将基因表达与STR进行关联分析,鉴定得到cis-eSTR。之后结合加权共表达网络分析(weighted correlation network analysis,WGCNA)及Gene Ontology(GO)富集分析,探索其在复杂性状中的潜在功能。共鉴定出25154对显著的cis-eSTR-基因表达关联,cis-eSTR主要分布于内含子区及转录起始位点附近。加权基因共表达网络分析显示,受cis-eSTR调控的基因被划分为多个功能模块,部分模块与奶牛的产奶及免疫相关性状显著相关。GO富集分析显示,这些模块广泛参与免疫应答、脂质代谢、细胞周期、DNA复制与稳定性等生物过程。多个关键基因(如IRF7、BoLA-DRB、CCT2等)在免疫调控与乳腺功能中具有潜在功能意义。cis-eSTR在调控奶牛基因表达和复杂性状方面具有重要作用。本研究所构建的cis-eSTR资源为奶牛健康等复杂性状的遗传机制研究和分子育种实践提供了功能注释信息标记。
